First real post here so please be gentle.
Background is I been ruminating for 6 months or so on building a budget Frankenstein rack-mounted vinyl system out of components I mostly already have. I picked up a couple of decent commercial amps from a store that was upgrading and was thinking of using a pair to separately power some full range speakers and subs using a mini-dsp as a crossover.
I realize i need a phono-stage for riaa and signal gain from the turntable, I'd also like a volume control and an input selector. I dug out Adcom gfp 555 i got some years ago thinking I'd find some cheap Adcom gfa 555s some day, it never happened.
Now I think this is a well regarded pre-amp and in particular the phono stage and I've read a few threads about recapping, rebuilding the PS and opamp swapping which I think is all within my capabilities. It's also rack-mountable so fits with what I'm trying to do. However, there's a lot of extraneous stuff on the amp that i don't need and am thinking of stripping out.
I'd like to remove the headphone amp, bypass all tone/mono/filter controls and remove relevant control knobs and buttons, remove the recording selector and possibly the switched and unswitched ac outlets. All I want and need is the phono stage, preamp, selector and volume.
Is this a crazy idea? To me it seems a doable project and a cost effective way to achieve my goal.
Secondly, I was going to use the mini-dsp 2x4 hd kit and put it in a rackmount enclosure but the enclosure costs just as much as the kit and seems to be overkill for a 4"x5" pcb. I have the idea to mount the dsp inside my pre-amp, routing the connections to the relevant inputs and outputs internally and reconfiguring the rca outputs at the rear of the amp. Possibly powering from the adcom PS. Maybe.
https://www.minidsp.com/products/minidspkits/minidsp-2x4-hd-kit-detail
Am I in danger of men in white coats throwing a butterfly net over me?
Should i waste anymore time thinking about any of the above?
Background is I been ruminating for 6 months or so on building a budget Frankenstein rack-mounted vinyl system out of components I mostly already have. I picked up a couple of decent commercial amps from a store that was upgrading and was thinking of using a pair to separately power some full range speakers and subs using a mini-dsp as a crossover.
I realize i need a phono-stage for riaa and signal gain from the turntable, I'd also like a volume control and an input selector. I dug out Adcom gfp 555 i got some years ago thinking I'd find some cheap Adcom gfa 555s some day, it never happened.
Now I think this is a well regarded pre-amp and in particular the phono stage and I've read a few threads about recapping, rebuilding the PS and opamp swapping which I think is all within my capabilities. It's also rack-mountable so fits with what I'm trying to do. However, there's a lot of extraneous stuff on the amp that i don't need and am thinking of stripping out.
I'd like to remove the headphone amp, bypass all tone/mono/filter controls and remove relevant control knobs and buttons, remove the recording selector and possibly the switched and unswitched ac outlets. All I want and need is the phono stage, preamp, selector and volume.
Is this a crazy idea? To me it seems a doable project and a cost effective way to achieve my goal.
Secondly, I was going to use the mini-dsp 2x4 hd kit and put it in a rackmount enclosure but the enclosure costs just as much as the kit and seems to be overkill for a 4"x5" pcb. I have the idea to mount the dsp inside my pre-amp, routing the connections to the relevant inputs and outputs internally and reconfiguring the rca outputs at the rear of the amp. Possibly powering from the adcom PS. Maybe.
https://www.minidsp.com/products/minidspkits/minidsp-2x4-hd-kit-detail
Am I in danger of men in white coats throwing a butterfly net over me?
Should i waste anymore time thinking about any of the above?
Welcome guy. There is a place in the forum for your first prentation called introductions, if desired.
Greetings
I think if you enjoy fabrication and modification, sure go for it. Otherwise, sell the Adcom and use that money to fund the project.
I attached a pic of my GFP-555 for layout reference.
Locating the power supply externally would be a useful step to gain room and reduce noise.
I think if you enjoy fabrication and modification, sure go for it. Otherwise, sell the Adcom and use that money to fund the project.
I attached a pic of my GFP-555 for layout reference.
Locating the power supply externally would be a useful step to gain room and reduce noise.
Attachments
@jordheis Yours is cleaner than mine. I like that everything is nicely spaced should make it easier to work on. I am definitely a parts changer and tinkerer by nature, even if I don't exactly understand how the amp. Definitely a fabricator, it'll at least look nice.
Yes, I thought about selling it and putting it towards something else. But whay?
Interesting with the power supply, not sure where I'd put it though. I read good things about doing this to my turntable. If it's just the transformer I think I could do that but if it's all the gubbins top left of the pcb then i don't think I'm capable. Do you see a problem with me trying to power the dsp by piggybacking of the Adcom supply? need 12v @ 2.5a or should I use a separate power supply? My thinking here that one would be better for two for noise.
Yes, I thought about selling it and putting it towards something else. But whay?
Interesting with the power supply, not sure where I'd put it though. I read good things about doing this to my turntable. If it's just the transformer I think I could do that but if it's all the gubbins top left of the pcb then i don't think I'm capable. Do you see a problem with me trying to power the dsp by piggybacking of the Adcom supply? need 12v @ 2.5a or should I use a separate power supply? My thinking here that one would be better for two for noise.
